In this Deep Space 1
image of comet Borrelly, sunlight illuminates the
bowling-pin shaped nucleus from directly below. At this distance, many
features are become vivid on the surface of the nucleus, including a
jagged line between day and night on the comet, rugged terrain on both
ends with dark patches, and smooth, brighter terrain near the center.
The smallest discernable features are about 110 meters (120 yards)
across.

Deep Space 1 completed its primary mission testing ion propulsion and
11 other advanced, high-risk technologies in September 1999. NASA
extended the mission, taking advantage of the ion propulsion and other
systems to undertake this chancy but exciting, and ultimately
successful, encounter with the comet. More information can be found
on the Deep Space 1 home page at http://nmp.jpl.nasa.gov/ds1/ .

Deep Space 1 was launched in October 1998 as part of NASA's New
Millennium Program, which is managed by JPL for NASA's Office of
Space Science, Washington, D.C. The California Institute of
Technology manages JPL for NASA.